Which interpreter on my computer should I use?

[snippsat]

Look at VS Code from start

I feel like I need to clean them up somehow.
Is there a way to do it?

No do not try to clean up if you don't know what you do.
Virtual environment can be cleaned up,but do not mess with OS install of Python.

Out of these 9 interpreters, which one to use?

The one you want to work with
You have Python 3.7,so use that.
Test with python3 and pip3 -V command line and see if it point to 3.7.

And why does it say (venv) in Python 3.6.5::Anaconda, Inc.?

Because it's made a virtual environment with Anaconda.
Look at my tutorial here to learn more about Anaconda.